@Sleepless Knight, I can see where you're coming from. Let me address your concerns as best I can.
1. Fuel. I can run a half with no in race fuel. I do not like to do this, nor do I recommend it. Sometimes I forget to take fuel during a race or in training. For a half, this is not disastrous. But the full is a very different matter.
Agreed. A full is absolutely different than a half marathon when considering fuel. It's entirely possible to finish a HM without taking in fuel. But finishing a marathon without fuel is significantly more difficult. I'll spare the math, but if a normal person with a normal metabolic efficiency where to run a marathon, they'd run out of glycogen in the body at about mile 16-19. If the person were to run slower, then that value could be extended outwards. If faster, then it would come sooner. Assumptions are being made with that calculation, but it goes to show how a HM could be done without fuel but a marathon is a different matter.
Now, the point would be asked then, could you practice fueling for a marathon in training without having to do 5-6 hour runs? Yes, you can. In my training programs I assign no fuel to be consumed on runs less than 90 min (electrolytes are acceptable). For all training runs longer than 90 min, nutrition/fuel practice is required. Unless someone is highly trained and looking to squeeze that last bit of juice then we'd play around with glycogen depletion training. But I don't pull that tool from the toolbox unless I have to. During those runs of longer than 90 min is when you find what works best for you. Do you like chews, gels, drinks, etc.? Do you like flavors or brands? How much water do you need to consume for things to appropriately digest? All these things can be accomplished during training runs that occur between 90-180 min.
The one thing you can't do on a training run limited to 180 min is test how your body will respond to fuel in the very late stages of a race. And that's a completely valid point. As most people find, as the race goes longer and longer the body becomes less and less tolerant to actually absorbing whatever you throw at it. The best thing to do is to load up on a decent amount of carbs in the early stages of the race when the body is more tolerant. That includes taking a bolus dose of carbs about 15 min prior to the start since this is like a "free time" where the body isn't focused on racing quite yet. Then load up on carbs early and often (with a plan in mind) as to continue to push back that glycogen depletion wall. The maximal per hour carb consumption limit is 90 g. If one were to consume 90g per hour, then a 250 pound male marathoner (just as an example and not to be a guess about you) running around a 6 hour marathon would consume around 560g carbs which by the average calculation would last a person ~37 miles (assuming they had the fitness to run a marathon around 6 hours). Far more than the 26.2 needed to go the distance. Although I don't recommend aiming for 90g since it's quite close to the tolerable limit. But just as an example.
So yes, limiting a run to 180 min in training could be a concern for the purpose of practicing late stage fuel consumption.
2. Bathroom breaks. Nobody likes to take these during a race. I've learned from the wrong kind of experience that it's not the end of the world. But again my longest run is a half. I know what to do to hopefully avoid it during a half, but will that translate to a full?
I can see this. I've typically found that consumption of water and pace will be a determining factor for whether one needs to use the bathroom. Generally that urge to go happens during the early stages of the race and not as often during the late stages (usually a tad more dehydrated in the late stages). For me, I practice this on a daily basis. I aim not to take in any liquids within 120 min of starting a run. I've done this thousands of times now and only a mere handful as it ever caused me an issue where I had the urge to go mid-run. So my suggestion is to practice on a daily basis the timing of liquid consumption pre-run and see if you get the urge.
But at the end of the day, even in the most planned outcomes, when you have to go you have to go. And there really isn't any amount of practicing that's going to change that. So if you find you train multiple 5-6 hour training runs and never have to use the bathroom, but on race day it happens. There's not much else to say except, time to go.
3. Physical impact of 6+ hours running. From what I've read my understanding is that mile 20 on is where the half gets interesting. Where it can start to really play with your mind. Maybe it's just my fear, but part of me feels like in order to know how to deal with the physical test that will come with this, I must have dealt with it in training.
Also valid. It is completely true that the point in the race that is usually the crux for most runners occurs around mile 18-20. It's true of those who do 11 mile max LRs and true for those who do 23 mile max LRs. Since the LR is going to be much slower than the actual race day pace (if following either Galloway or my plan correctly), then you won't really be simulating that true feeling that comes at mile 20. But we can get close to simulating it.
Galloway gets there by providing a single day stimulus up to that 24, 25, or 26 mile max run. I provide that stimulus by not allowing you to be "fresh" entering the LR. Instead of the super LR, you instead do two runs consecutively that carries some fatigue from one day to the next. The idea is that allowing the body some rest between these bouts of exercise mitigates the risk of a super LR but yields a similar training stimulus both physically and mentally. And that's an important consideration with my plans. While I might not do a 24, 25, or 26 mile LR, it by no means means my plans are easier than Galloway's. The plans I write are tough at the end of them, but the payoff can be big and it's my goal to get you to the starting line as healthy as I can. There's risk in consecutive LRs and there's risk in a super LR. Neither is the right way, just two different ways to garner the same adaptation response in the body to yield the necessary tools to finish the race.
One thing I offer is to consider my consecutive training runs not as they appear. On the schedule it might say 7 LR + 11 LR on the weekend. That 11 LR isn't like training for miles 0-11 of the marathon. Because of the fatigue from the 7 mile LR the day prior, it's more like training for miles 14-26. Is it a perfect simulation? Most definitely not. The end of the marathon is super tough. It generally takes me 2 weeks to recover from the race and another 2-4 weeks before I feel normal again. That's not true of a single training run that I do. By the time that 2.5 hr training run comes on Sunday (granted at MP + 9% so it's slower), I'm ready for another 1.5-2 hr training run on Tuesday. I'm able to stack multiple quality workouts close to each other because I don't require a massive recovery period. But as soon as I cross that threshold and go to my marathon pace and distance of 26.2 miles, then suddenly I'm taking as much as 4-6 weeks to fully recover and be normal again. So that's 2 days vs 4-6 weeks. A significant amount of damage occurs during a marathon. Dependent on how close you race to your maximal capability makes that recovery period longer and longer.
But at the end of the day, I won't be able to squash that fear for you. Only you can take that leap of faith that says "yes, a 3 hr run/walk max LR can lead to a successful marathon day". But just remember that the LR is merely a single piece in the entire puzzle. It gets a lot of buzz, but no one run defines the training cycle. It's the cumulative effect of all the training put together that leads to a successful day. I've had races where I missed or had to cut short the final LR. I never hit the maximal distance. And yet on race day, I usually do as good as I expected. And that's because of all the other 99% of training runs, not simply the one longest one.
1. Real feedback on what's going right and what isn't going right. Ability to safely adjust training during a period when a max run of 1 hour is a huge sacrifice considering 6-7 days of work a week with long hours to boot.
Valid. My goal is to make the training plan fit around your life. Not make you fit your life around the training plan. You tell me what you can do. I tell you what to do with that time. But I'm always honest in what I believe the outcome will be. So someone could come to me and say I want to run a BQ but I can only train one day per week (an admittedly extreme example) and I'll simply say that it's going to be a really tough endeavor.
And I'm also here every step of the way. Something comes up and almost always in less than 24 hrs I'll tell you how to adjust the plan. I'll look at what I wrote, assess your situation, and then offer a suggested change. I'm always looking to maximize your performance on race day as best I can and that includes making multiple alterations along the way if necessary.
2. A concern that the Galloway plan calling for intense finishes to the running week will make it difficult to recover and risk over training heading into marathon weekend.
Valid. While Galloway's plan will require some serious recovery from the longest run which pushes out the next quality workouts, my plans generally stack them much closer together. But the key difference is that my plans typically don't allow you to fully recover during the training. They keep a low/medium hum of fatigue throughout. The goal for me is to progressively build that fatigue slowly so much so that you barely notice it's building. But ask others what that true taper feels like. Come race day you're going to feel like you've never felt before and realize just what that low/medium hum felt like throughout training.
3. I've learned so much from the Galloway plan. In fact it's the very reason why I'm still at this. But that doesn't mean that I can't learn more and possibly find a way that works better for me.
Just like you, I continue to read. I can not become complacent that I know everything there is to writing training plans. I don't and never will. And that means that plans I wrote 12 months ago look completely different than they do now. I'm always adapting my training techniques based on the individual responses I get from the different people. Some people respond differently to different stimuli. Some people handle more or less training better. Always trying to get a good read on the users so I can better figure out their puzzles. So while I know a lot, I can absolutely keep learning and I think that's true of pretty much everyone.
Galloway's no different. I was listening to a podcast with him a few months ago. They combed their dataset and came to some new conclusions. He then rolled out those conclusions among his users to try and hone in his technique even several decades old now.
I really appreciate this. While I do not relish even the thought of 5-6 hour runs regularly, based on my most recent fastest time of 3:06 in a half, I have to operate under the assumption that I'm looking at 6+ hours to finish the full. My January attempt to increase my speed ended in runners knee. Time off and resuming training previous speeds proved enough to finish all 3 Dark Sides races. This time around, I'm hoping to address the issues that caused the runners knee before it causes a problem.
The speed thing is a matter of how it went about being accomplished. Lots of different ways to attack it and I wouldn't be ready to toss in the towel on improving speed quite yet. Lots of tools in the toolbox to try and solve this one. Another one of my core philosophies is balance in training. It may simply be that you upset the balance in training and this led to some issues you were seeing.
) but in the past I have felt like I needed that time on my feet to keep the later stages of the race from becoming a death slog. 
